Embodiment relate to a light emitting device, an electrode structure, a light emitting device package, and a lighting system.
Due to their physical and chemical characteristics, Group III-V nitride semiconductors are being esteemed as core materials for light-emitting devices such as light-emitting diodes (LEDs) and laser diodes (LDs). Each of the Group III-V nitride semiconductors is formed of a semiconductor material having a compositional formula of InxAlyGa1-x-yN (0≦x≦1, 0≦y≦1, 0≦x+y≦1).
LEDs are a kind of semiconductor device that is used as a light source or uses the characteristics of compound semiconductors to convert electricity into infrared rays or light, thereby receiving or transmitting signals therebetween.
These semiconductor based LEDs or LDs are widely used in light-emitting devices, and are applied as light sources for various products such as keypad light-emitting units of mobile phones, electric light panels, and illumination devices.